Stroke-cushion attachment for shaking-screens.



0.. 672,420. Patented Apr. I6, I90. A. L. LEGRAND. STROKE CUSHION ATTACHMENT FOR SHAKING SCBEENS.

(Applicatiop filed. May '10. 1900.:

(No Model.)

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AUGUSTUS L. LE GRAND, OF WEST PITTSTON, PENNSYLVANIA, ASSIGNOR OF ONE-HALF TO JOHN N. THOMAS, OF SAME PLACE.

STROKE CUSHHQN ATTACl-ill/l ENT FOR SHAKlNG -SCREENS.

SPECIFICATION forming part of Letters Patent No. 672,420, dated April 16, 1901.

Application filed May 10, 1900. Serial No. 16,205. (No model.)

To all whom it may concern: from the spirit or principle of the in ven- Beit known that I, AUGUSTUSL. LE GRAND, tion; but the preferred arrangement thereof acitizen of the United States, residing at West is shown in the accompanying drawings, in

Pittston, in the county of Luzerne and State which'- of Pennsylvania, have invented a new and Figure 1 is a side view of a pair of shaking 55 useful Stroke-Cushion Attachment for Shakcoal-screens fitted with the attachment coning-Screens, of which the following is a specitemplated by the present invention. Fig. 2

fication. is a sectional end elevation on the line 2 2 of In the separating and grading apparatus Fig. 1. Fig. 3 is a detail sectional view on used in and about collieries there are usually the line 3 3 of Fig. 2, showing more plainly 6o employed what arecommonly known in theart the rocker-support for the individual cushas shaking-screens. These screens are arioning-springs. Fig. 4 is a sectional View ranged in tiers in successive order, according through a pair of the individual cushioningto the mesh of the screen, to provide for gradsprings, showing the mounting of the rocker- ,15 ing or assorting the coal into different sizes, supports therefor within a single bearing- 65 and said screens are usually of great Weight plate. and length. Ordinarily the momentumthere- Like numerals of reference designate correof is necessarily so great as to transmit a viosponding parts in the several figures of the lent jar to the driving or operating mechandrawings.

ism at the end of each stroke, thus rendering As already explained, the invention is nec- 7o the motion of the screens not only jerky, but essarily applicable for use in connection with also causing a severe vibration of all the parts the shaking element of a separating or gradof the machinery, and especially the driving ing apparatus, but is especially designed for or operating mechanism. This ocoasionsfreuse in connection with the ordinary longituquent breakages and constant impairment of dinally vibrating or shaking screens used in the driving mechanism, thus entailing he a separating or grading apparatus for coal, quent repairs and adjustment of the different so for illustrative purposes the invention is parts of the machinery associated with the shown in the drawings as applied to screens screens. of this character.

o Screens of the character referred to are used Referring to the drawings, the numerals 1 in different relations, but those to which the 1 designate a pair of longitudinally vibrating invention is specially applicable constitute a or shaking screens of the ordinary type, arpart of the grading apparatus for separating ranged one above the other and constituting the coal into its different sizes or grades; and a part of the usual tier or succession of 5 the main and primary object of the invention screens employed in coal-grading apparatus; is to provide novel and efficient means for not but inasmuch as the .manner of hanging and only rendering the motion of the shakingoperating all of the screens is the same it is screen uniform and steady, but at the same deemed sufficient to illustrate a pair of these time providing an effective cushion to comscreens. The said screens are fitted with the 0 pletely absorb the momentum of the screen usual sieves, and each of the same is pivot- 0 at the ends of its strokes, thus entirely relievally suspended from a plurality of swinging ingthedriving mechanism from jarand strain. hanger-links 2, pivotally connected at their To this end the invention consists in the lower ends with the screen-frames, at the novel constructionand arrangement of cushsides thereof, and pivotally attached at their 5 ioning attachment hereinafter more fully deupper ends, as at 3, to a supporting-beam 4 scribed, illustrated, and claimed. ,or other fixed point of support, and each of the The essential features of the attachment to shaking-screens 1 is designed to have a 1oninsure a cushioning of the screens at the ends gitudinally reciprocating or vibrating motion of the strokes thereof are necessarily suscepimparted thereto by means of the pitmen 5, 5-6 tible to some modification without departing which are pivotally connected with one end of the screen through the medium of a coupling-rod 6, mounted in suitable brackets 7, fitted to the screen frame or body. The other ends of the pitmen 5 for each shaking-soreen are carried by the eccentric-straps 8 of the eccentrics 9, mounted on a driving-shaft 10, which is usually common to all of the screens; but the eccentrics are necessarily arranged in different relations to provide for imparting opposite movements to adjacent screens. These features constitute common appurtenances of the ordinary shaking-screens, and in carrying out the present invention there is associated with each screen a stroke-cushioning attachment, which preferably includes a pair of oscillating levers 11, suitably connected with the same end of the screen. The pair of oscillating levers for each screen are preferably of a T shape, consisting of the straight stems 12 and the crossarms 13 at one end of the said stems. The said straight stems 12 of each pair of oscillating levers are pivotally connected at their lower ends, as at 14, with one end of the shaking-screen with which they are associated, said pivotal connections 14 being preferably effected by fitting the lower ends of the levers directly upon the extremities of the coupling-rod 6 for the screen.

The oscillating levers ll of each pair for each shaking-screen are mounted at their upper ends upon a supporting-shaft 15, whose extremities are arranged in the brackets 16, fitted to the supporting-beam 4: or other fixed point of attachment. The said shaft 15 constitutes a pivotal support for the said levers 11, whereby the same may be readily rocked thereon. The cross-arm 13, at the upper end of each oscillating lever 11, projects at equal distances beyond each side of the main stem of the lever and has pivotally connected to its opposite extremities oppositely-arranged niotion-transmitting stems 17, extending upward loosely through openings 18 in a cross-beam or support 19 and having coiled upon their upper end portions, above said beam or support, normally-compressed cushioning-springs 20, which are interposed between the socketed holding-caps 21 and 22,also arranged upon the stems. While the stems 17 constitute motiontransmitting elements, it will be understood that the motion-transmitting device proper consists not only of the stems, but also of the oscillating levers 11, carrying the same. The upper extremities of the motion-transmitting stems 17 are threaded to receive thereon the adjusting-nuts 23, working above the upper holding-caps 21 to provide for regulating the tension of the springs 20, and the lower socketed holding-caps 22 constitute rocker heads or supports for the lower ends of the springs, each of the said rocker-supports 22 not only having a socket portion to receive therein the lower end of the spring associated therewith, but also provided at its under side with oppositely-arranged rounded journal-lugs 24:, which are adapted to turn in the correspondingly-shaped bearing-seats 25, formed in the base of the flanged bearing-plate 26, mounted on top of the cross-beam or support 19. The openings 2'7 through the lower holding-caps or rocker-supports 22 are larger than the stems 17 passing therethrough to permit of the'rocking movement of the said supports 22, and at this point it will be observed that to provide for a compact arrangement of the stroke-cushioning attachments for adjacent screens the said attachments are arranged side by side and the springs for adjacent screens are grouped in pairs, so that the lower rocker-supports 22 therefor may be arranged side by side, so as to work within a single bearing plate or casting 26, as plainly illustrated in Figs. 2 and 4 of the drawings.

In the operation of the screens by reason of the T-shaped construction of the oscillating levers 11 the motion of the screensis transmitted directly to the cushions or springs associated with both ends of the cross-arms of the levers, thus insuring a steady and uniform movement of the screens, besides providing for the complete absorption of the vibration or strain occasioned by the momentum of the screens at the ends of the strokes thereof, thus entirely relieving the driving mechanism from the jar or strain.

It will be further observed that the cushioning attachment is itself relieved from undue strain by reason of providing the rockersupports 22 for the cushioning-springs, so

that they will accommodate themselves to any lateral thrust which may be imposed thereon.

The invention has been represented in its simplest aspect; but it will be obvious that the T- shaped levers may be braced or snitably strengthened in any desired manner, and, in fact, any suitable changes in the form, proportion, and minor details of construction may be resorted to without departing from the principle or sacrificing any of the advantages of this invention.

Having thus described the invention, what is claimed as new, and desired to be secured by Letters Patent, is

1. The combination with the shakingscreen, and the swinging supports and driving mechanism therefor, of a cushioningspring for the screen having an individual rocker-support at one end independent of the screen-supports, and a motion-transmitting device having a member connected with the spring opposite its individual rocker-support, said motion-transmitting device being also operatively connected to the screen.

2. The combination with the shaking-screen and the driving mechanism therefor, of separate cushioning devices supported independent of the screen and spaced apart, and a motion-transmitting device having a single connection with the screen and separate connections respectively with the individual cushioning devices.

3. The combination with the shakingsta led screen, and the supports and driving mechanism therefor, of normally-compressed strokecushioning springs supported independently of the screen and its support, and arranged in spaced parallel relation, and means for transmitting the motion of the screen in both movements thereof to said springs, and acting simultaneously in opposite directions on said springs.

4. The combination with the v shakingscreen, and means for reciprocating the same, of separate cushioning devices supported independent of the screen and spaced apart, and a single oscillating motion-transmitting element having a single connection with the screen and separate connections respectively with the individual cushioning devices.

5. The combination with. the shakingscreen, and means for reciprocating the same, of separate normally-compressed cushioningsprings supported independent of the screen and spaced apart in parallel relation, and a single oscillating motion -transmitting element having a single connection with the screen and separate connections respectively with the individual cushioning-springs.

6. The combination with the shaking-screen and means for reciprocating the same, of oppositely-arranged cushioning devices, an oscross arm,

and normally-com pressed cushioning-springs connected with said stems.

8. The combination with the shakingscreen, and means for reciprocating the same, of an upright cushioning-spring having an individual rocker-support at one end, entirely independent of the support for the shakingscreen, and a motion-transmitting element having an operative connection With the opposite end of the spring and also with the shaking-screen.

9. The combination with the shaking-screen and means for reciprocating the same, of normally-compressed cushioning devices having rocker-supports for their lower ends, a T- shaped oscillating lever having the main. stem thereof connected with the shaking-screen, and motion-transmitting stems pivotally con neeted respectively to opposite ends of the and also connected With said springs, substantially as set forth.

10. The combination with the shakingsereen and means for reciprocating the same, of stationary bearing-plates having bearingseats therein, normally-compressed cushioning-springs, rocker-supports for the lower ends of the springs, said rocker-supports being provided with journal-lugs mountedin said bearing-seats, a lever pivotall connected with the screen and provided with a cross arm, and motion-transmitting stems counected respectively with opposite ends of said cross-arm and also operatively connected with said springs.

In testimony that I claim the foregoing as my own I have hereto affixed my signature in the presence of two Witnesses.

AUGUSTUS L. LE GRAND.

Witnesses:

SAMUEL C. WEBB, HENRY GAUPP. 

